package com.team.order.utils;

import lombok.RequiredArgsConstructor;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * @author 梁国瑞
 * @version 1.0
 */
/* 全局唯一ID生成器 */
@Component
@RequiredArgsConstructor
public class RedisIdWorker {

    //开始时间戳
    private static final long BEGIN_TIMESTAMP = 1640995200L;
    //序列号位数
    private static final int COUNT_BITS = 32;

    private final StringRedisTemplate stringRedisTemplate;

    public long nextId(String keyPrefix) {
        // 1. 生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;
        // 2. 生成序列号
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        String key = "icr:" + keyPrefix + ":";
        long count = stringRedisTemplate.opsForValue().increment(key + date);
        // 3. 拼接返回
        return timestamp << COUNT_BITS | count;
    }

}
